The lawsuit alleges that the law, passed by the Georgia General Assembly last year, has a disproportionate impact on African-Americans, Latinos and Asian-Americans who want to become registered voters.

About 80 percent of applications put on pending status were submitted by those minority groups, according to the lawsuit.

Under the law, registrations can be placed on hold because of a missing hyphen, an extra space or the use of a nickname in official government records.

"It imposes unnecessary and discriminatory burdens on the voter registration process," according to the lawsuit, filed by the Lawyers Committee on Civil Rights Under Law, which is representing several civil rights organizations in the legal action.

The plaintiffs include the Georgia Coalition for the Peoples' Agenda, Asian Americans Advancing Justice-Atlanta, the NAACP of Georgia, the New Georgia Project, the Georgia Association of Latino Elected Officials and ProGeorgia.

Kemp has said the "exact match" law is legal, and anyone placed on the state's list of pending voters can still cast a ballot if they show valid photo ID either when they go to vote or beforehand.

A spokeswoman for Kemp called the lawsuit a publicity stunt that will waste taxpayer money when the state defends the law in court.

"Their claims are completely bogus," said spokeswoman Candice Broce. "The so-called 'exact match' law was passed by the Legislature and signed by Gov. (Nathan) Deal. It mirrors a Florida law recently upheld in federal court. The 53,000 Georgians cited in the complaint can vote in the Nov. 6 election. Any claims to the contrary are politically motivated and utterly false."

The option is spreading at a time of heightened fear of foreign interference in U.S. elections. It has been used in a few local elections and will be available to some voters in the 2020 presidential caucuses.